hi there ,
got a 3door mk4 1.8 20v non turbo, ive lowered and bunged bigger wheels on, but tuning wise havent done nowt yet, from what ive read on mk4 website u can get a filter+exhaust and a chip and that will take you to not far off the 150bhp mark, which is what the standard 150 turbo is!, so you can tune em havent bothered yet as engine now done 75000 an loosening up like mad all gone loose and very nippy at the mo! so will wait a bit longer till start tuning